Monday, April 30, 2012

Betta Fish (Betta splendens) Care


True to their name, Siamese fighting fish (Betta splendens) were originally domesticated for fighting around 200 years ago in what is now Thailand. At first they were collected from the wild and made to fight, but soon the villagers realized they could breed the most aggressive fish. Thus the domesticated betta was born. When the long-finned varieties and vibrant colors began emerging betta fish also became known as pets.

The most common tail shapes are veiltail, crowntail, halfmoon, plakat, double tail, and delta tail. These are the types you are most likely to encounter at pet stores. I have included a few pictures below. Unlike with goldfish, the fins don’t affect the care requirements. 

Crowntail betta (Betta Slave @

Veiltail betta (chrissylee13 @
Halfmoon betta (copperarabian @
Unlike many other fish, bettas can actually drown. This is because they possess a special organ called the labyrinth organ, a specialized folded sac that enables them to utilize atmospheric oxygen. This evolved because many betta and their relatives live in oxygen-poor environments throughout part of the year in the wild.

Now I know you’re thinking “just because they can use atmospheric oxygen doesn’t mean they can drown.” This is untrue. Betta are obligate air breathers and actually have to use the labyrinth organ to breath as their gills aren’t able to pull enough oxygen from the water.  So without access to the surface a betta can drown.

Minimum tank size

No fish should ever be maintained long-term in a tank smaller than one gallon. Betta are no exception. The bare minimum tank size for any fish is one gallon of water. However, I believe betta and other fish will fare better in tanks that are 5 gallons (19 L) or larger.

Small tanks are hard to heat. They lose heat easily and can heat up too fast due to the small volume of water. The water chemistry can also change rather rapidly in a tank of this size as there is less volume of water to buffer a change. One small decaying piece of food will cause the ammonia to rise in a 2 gallon (7 L) tank at a much faster rate than in a 10 gallon (38 L) tank. A 5 gallon (19 L) tank is also the smallest tank that can hold a stable cycle (ie a colony of beneficial bacteria to change your fish's harmful waste into a non harmful state). A simple google search will give you many guides on how to cycle a tank. Having a cycled tank means less water changes and not having to remove the fish to do a 100% water change. This will cause less stress for your betta. And less stress equals a healthier betta.

Many people (sale reps included) will advise against a large tank for a betta, saying they “freak out” in large spaces. This actually has some truth to it. Betta and fish in general don’t like large open spaces. Many of the fish commonly found in the freshwater aquarium world are forest fish that evolved in streams that run through dense forests. This means the light is dampened and there are often lots of small branches fallen in the water in which fish can hide from predators. In the aquarium they maintain this innate desire to hide from (imagined) predators in cover.

What this all means is that betta, and any fish for that matter, can and do “freak out” in large open spaces because they are not comfortable out in the open. When given cover, betta tend to be less shy because they know if something spooks them, they can always run and hide. Without that “safety net” then they often become frantic. Think of it this way; would you rather be out in the middle of a field without any trees or tall grass for miles or watching the field from the tree line?

Tank decorations will really help enhance your betta’s quality of life as well as colors. When betta are stressed, they will wash out their colors. Many male betta enjoy caves that they can rest in. Female betta enjoy decorations that reach up close to the surface of the tank. Just make sure that whatever holes are in your decorations are either too large for the fish to get stuck or too small for the fish to get into at all.

One final note about aquariums for betta is that they should always have a lid. Betta fish are notorious jumpers, and many keepers have lost betta when they forgot to put the lid back on the aquarium. These little escape artists will even find the holes in the top of your hood if they are large enough. Be sure to cover all spaces in the hood. Old egg cartons and leftover craft canvas work great for this.

Temperature range

3.5 month old juvenile (GeinahClarette @
Betta fish are tropical fish. This means that they live in rather hot regions. There are native populations in Thailand, Vietnam, Laos, and Cambodia. For anyone who has never been to that part of the world, it is hot and humid. This means that betta fish are adapted to living in these hot and muggy conditions and that they need a temperature between 76F (24C) and 86F (30F) to thrive. They become sluggish and sickly in cooler water and may refuse to eat. Or if they do eat, your betta may not be able to digest the food as their metabolism depends on body temperature which is externally regulated. Warm water helps boost their immune system and make them active. 

Water quality

When it comes to pH and hardness, betta fish are very unfussy. They will tolerate most normal ranges from pH 6.0 to 8.0. The most important thing is that your betta have a stable pH; just because they are comfortable in a wide range of pH doesn’t mean they can deal with a fluctuating pH which is only achieved through regular water changes. Some people have reported health problems associated with very hard water; however this appears to be few and far between.
As with any fish tank, the ammonia and nitrite should always be 0 ppm. In a cycled aquarium (which won’t happen in less than a 5 gallon (19 L) tank) this is nothing to worry about. The ammonia that your fish excretes will be changed into a harmless substance called nitrate by the beneficial bacteria that make up a cycle. Nitrate is controlled through regular water changes. Provided you keep up with them, nitrate is nothing to worry about.

An important aspect of keeping water quality top notch is a filter. However since filters are only useful in a cycled tank, if you choose to keep your betta in a tank less than 5 gallons (19 L) a filter isn’t a good idea. It won’t improve water quality and will just push your fish around. Betta come from very slow moving waters and any filter flow should be lessened to prevent stress on your fish. My favorite filter to use with betta is a sponge filters as they produce the least current and are the cheapest. However, they do make a bit of noise, so if you have your tank in your bedroom, you might want to look for another option.


Most betta are unfussy about food and will take anything you offer them. However, just like a kid with candy, just because they like it doesn’t make it good for them.  Because betta are carnivores, they need a food that is high in protein (above 38% protein as listed on the label). A good way to check the quality of a fish food is to look at the ingredients list. If some kind fish or krill is listed as the first ingredient then you know the food is high quality. My favorite foods to feed my betta are New Life Spectrum’s betta formula and Omega One betta pellets. Pellets are a better food for betta because flakes are known to cause issues with bloat. 

Bettas enjoy planted tanks (PandaBetta @

Like a dog or a cat, there are special treats that you can give your betta. Frozen bloodworms or frozen brine shrimp are like filet mignon to a betta. Freeze-dried food is a good alternative for the more squeamish, but it shouldn’t be given on a regular basis due to issues with bloating of the GI tract. If you really feel like treating your betta, you can venture into live food like brine shrimp for him or her. Many fish specialty stores will carry treats like this.

Tank mates

A common myth about betta is that they have to live alone due to their high aggressiveness. This is not true. Betta can make great additions to a proper community aquarium, but not just any community will do. Since betta are small, the inhabitants can’t be too large to eat them like oscar (Astronotus ocellatus) or aggressive towards betta like gourami (Osphronemidae) or colorful enough that betta might mistake them for another betta like guppies (Poecilia reticulata).

That being said there are a lot of good tankmates for betta, provided the tank is 10 gallons (37 L) or larger. Many of the small tetra species like ember tetra (Hyphessobrycon amandae) and Pristilla tetra (Pristella maxillaris) make great tank mates under one condition: the tetra are in a group larger than 8. Tetra are schooling fish and do show aggression within the school. If there are not enough neon tetra around, they will begin to pick on your betta. I compiled a more complete list of suitable small schooling fish tankmates below. I encourage you to use the scientific names for reference as the common names will change from location to location.

  • X ray tetra/Pristella tetra (Pristella maxillaris)
  • Head and tail light tetra (Hemigrammus ocellifer)
  • Ember tetra (Hyphessobrycon amandae)
  • Harlequin rasbora (Trigonostigma heteromorpha)
  • Lambchop rasbora (Trigonostigma espei)
  • Glowlight tetra (Hemigrammus erythrozonus)
  • Black neon tetra (Hyphessobrycon herbertaxelrodi)

You also have the option of keeping substrate (bottom-swimming) fish with betta. Here you have many options with small catfish and loaches. Again, most of these fish are schooling fish and need to be in groups of 8 or more. Without sufficient group size, these fish will be very shy and withdrawn. These fish need a tank larger than 15 gallons (57 L). Here is a short list of suitable substrate fish with added notes about their care:

  • Oto catfish (Otocinclus macrospilus) groups of 3-4; need a mature, planted tank
  • Kuhli loach (Pangio kuhlii) groups of 6 or more; provide lots of hiding places
  • Bronze cory (Corydoras aeneus) groups of 6 or more; also comes in albino
  • Pepper cory/Salt and pepper cory (Corydoras paleatus) groups of 6 or more
  • Tail spot cory (Corydoras caudimaculatus) groups of 6 or more
  • Bristlenose pleco (Ancistrus sp.) best kept singly; needs large aquarium to house multiple
  • Leopard cory (Corydoras leopardus) groups of 6 or more
  • Bandit cory (Corydoras metae) groups of 6 or more

As I am writing this for the beginner hobbyist all of the fish I included are hardy and easy-to-care-for fish. There are other compatible fish, but they are more difficult to keep alive and not for the beginner fishkeeper. To find these, I encourage you to do your own research.

While there are many good choices for betta tankmates, I feel the need to mention fish that are not suitable to be kept with betta. Some of these fish are aggressive and notorious fin-nippers even in proper group sizes, some can become targets for betta aggression, and some will gobble up a betta without any hesitation. Either way, they have aspects that make them bad betta tankmates.

  • Angel fish (Pterophyllum sp)
  • Oscar (Astronotus ocellatus)
  • Other cichlids (Cichlidae)
  • Guppies (Poecilia reticulata)
  • Platies (Xiphophorus maculates)
  • Swordtail (Xiphophorus hellerii)
  • Mollies (Poecilia sphenops or Poecilia latipinna)
  • Blue gourami (Trichopodus trichopterus)
  • Dwarf gourami (Trichogaster lalius)
  • Pearl gourami (Trichopodus leerii)
  • Other gourami (Osphronemidae)
  • Kissing gourami (Helostoma temminkii)
  • Goldfish (Carassius auratus auratus)
  • Tiger barbs (Puntius anchisporus)
  • Serapae tetra (Hyphessobrycon eques)
  • Black widow tetra/black skirt tetra (Gymnocorymbus ternetzi)

It will also surprise you to learn that some female betta fish can live with other female betta fish. Males should never be kept together. However, this female betta tank is not your everyday tank. This tank is called a female betta sorority. The tank needs a lot of decorations and most people choose to accomplish this by heavily planting the tank or adding so many fake plants you can’t see the other side when looking through it. For a sorority you will need a minimum of a 10 gallon (37 L) tank and 5 females. Any less and you have a good chance of one or two females ganging up on the others. More females means spreading out the aggression more. A longer tank is always better than a taller tank with a sorority. If you want to peruse this avenue, I suggest you do more research and talk to people who have maintained a sorority. They’re not for the beginner betta keeper. 

Successful betta sorority (kfryman @


Live plants are a great enhancement to your betta’s tank. For the more adventurous you can research how to set up a planted tank, but for those of us who just want one or two easy live plants. I’ve got some suggestions for you. Anubias (Anubias barteri) and java fern (Microsorum pteropus) are two great beginner plants. You can easily find them at your local pet store, and they don’t need much light. Anubias has large strong leaves that betta like to rest on, and Java fern makes a great betta play ground with its many leaves growing to the clouds.

Smashing the myths

Due to the popularity of betta fish, there are many myths that surround these beautiful creatures. The first I hear used to justify keeping betta in tiny (less than a gallon or worse a litre) containers: wild betta live in mud puddles. While I am not going to deny that due to seasonal water flow in their native range betta can survive in small amounts of water for part of the year, I am going to point out that there is a large difference between our captive betta fish and their wild counterparts. Most of the fish available today are hundreds if not thousands of generations removed from the wild. Remember, betta have been bred in captivity for around 200 years. If you were to plop a pet store betta into the wild, it would die within weeks. In fact, many of these betta that are caught in “mud puddles” would have soon died when the puddle dried out in a few day. Just because an animal has evolved to periodically withstand harsh conditions doesn’t mean they should be forced to live in them. Betta fish evolved to survive in small spaces during extreme circumstances (ie drought) but need at least a gallon of water to live to healthily.

The second common myth I have seen and heard is the betta in a flower vase ecosystem myth. People believe that it is a natural ecosystem because the fish eats the roots and the plant eats the fish’s waste. This is not only completely false but cruel. There is no way to completely replicate a natural ecosystem in a volume of water that small; even in massive tanks at public aquaria they cannot replicate a natural ecosystem. Also betta don’t eat plants, so when a betta is kept in this type of tank, they slowly starve to death. Betta fish are carnivorous and need a lot of protein in their diet as I have already mentioned. The plants also take up surface area and without access to surface air, the betta will drown.

(copperarabian @

Many people don’t like betta fish. They see them as boring and unattractive. This is probably so because they have never seen the fish in a proper habitat. In properly decorated and heated 5 gallon (19 L) tank, betta fish blossom. They are a wonderful dorm or apartment pet. For those who want fish but don’t have the room for a large community tank, a 10 gallon (37 L) with a betta and either substrate fish or schooling fish is a great alternative. And for those who have even less space, a 5 gallon (19 L) tank will easily fit atop a desk. They make a great kitchen buddy, too. If you are just getting into the hobby or a long-time veteran, a betta fish can be a great subject for a small aquarium or a chance to try something new like a micro planted tank.

Works referenced

“Betta splendens” Regan, 1910.” Updated 15 Nov 2011. Retrieved 24 April 2012.

Christie F. 2004. “Betta 101.” Retrieved 20 April 2012.

Frequently asked questions on Siamese fighters.” Updated 2 June 2011. Retrieved 25 April 2012.

Helfman, G. S., B. B. Collette, D. E. Facey, and B. W. Bowen. 2009. The Diversity of Fishes: Biology, Evolution, and Ecology, 2nd edition. Wiley-Blackwell, West Sussex, UK.

The History of Betta Fighting Fish.” Updated 2009. Retrieved 25 April 2012.

Ng, Heok Hee. 18 April 2011. “Quick guide to anabantoids.” Retrieved 20 April 2012.

Parnell, Victoria. 30 June 2006. “Feeding your Betta.” Retrieved 23 April 2012.

Warren, Eleanor. 2006. “Plight of the Betta.” Retrieved 25 April 2012.

Thursday, April 26, 2012

What to do with your aquariums in a power outage

So this morning I woke up to the sound of the filters in my goldfish tank turning off. I muttered a few four-letter words and got out of bed early. The beeping of my fire alarm let me know the power had indeed gone out. No big deal for me; just a minor annoyance in the day. But I’ve dealt with power outages before. For those of you who haven’t, here are a few tips to get you through them with your fish and sanity intact.  


First thing: Don’t panic.


It’s usually not as bad as it seems. Trust me. Fish are amazingly resilient, and unless you are keeping and breeding a very rare and sensitive species, you’ll probably come out just fine. Take a breath and reach for a flashlight.

Second: Assess the situation


Why did the power go out?  You don’t have the find the exact cause, but often the weather will give you a hint. If it’s snowing or icing, that’s probably your cause right there, and conserving heat will be your main focus. If you hear thunder, the storm probably caused it. While you are doing this, think about your safety first and foremost. Never do anything to endanger yourself. If you’re gone, who will take care of your family and fish?

Third: React


The two things you need to take care of are conserving heat and saving the beneficial bacteria in the filter. When your house temperature will drop take care of the heat first. Wrap your tanks in blankets or towels and secure them with string, tap, or clothespins. This will help keep the heat in. It may sound and look funny, but think of how a warm blanket on your lap keeps the heat contained.
Taking care of your good bacteria is more difficult and gets harder the longer your power is out. The beneficial bacteria live on your filter media (filter cartridge) and will be fine just sitting in your filter for about three hours. If your filters have a nasty habit of draining when they are turned off (like mine today) just take a few scoops of tank water and fill the filter. This will also prevent your filter from running dry if the power returns and you aren’t there to fill it. It’s a good idea to do this once an hour to keep feeding your good bacteria.

Once your power outage has gone beyond 3 hours, leaving the filter media in your filter is going to cause the bacteria to die and the tank to have a mini cycle when the power comes back on. At this point you are going to want to put the filter media inside the tank. This is a double-edged sword because both the bacteria and your fish need oxygen to survive. Here is where the need for a battery-powered air pump comes into play. There are some sold specifically for aquariums, but you can also find ones made for bait-buckets at an outdoors store. You can either just insert a bubble wand into your tank or set the system up with a sponge filter. This isn’t something to make when you power goes out, but something to have ready before hand. I will go into further details about it in the next section.

If your power outage persists for a few days and you have access to clean water, doing a water change on the tank earlier than normal is a good idea. To be safe, ad a double dose of your de-chlorinator. If you cannot access clean water, don’t just take water from outside as you have no clue what organisms are growing it in. The risk of infecting your fish is too great. Always remember, think of yourself first.

While the power is out, don’t feed your fish. Again, they are hardy, and a healthy fish can easily go a week without eating. Keeping waste down is a priority during times like this. This may mean removal of plants. Without a good light source to photosynthesize, plants actually compete with the fish for oxygen and start to die, releasing ammonia into the water. If you just have a few plants, remove them and place them in a clean (never been used with chemicals) bucket with tank water near the window. With a heavily planted tank, you are best just leaving the plants where they are as removing them would do more harm than good.

Since I also have a pond to worry about, I thought I would add a few more notes for people with ponds. The single most important thing you need to worry about is water movement. It’s what keeps the pond oxygenated in the summer and prevents freezing in the winter. A large battery-powered air pump is going to be best for this. If the power goes out in a storm, the rain action on the surface should be sufficient for a few hours, but after the storm if the power isn’t restored soon, you could be in trouble. For lightly stocked ponds the danger is going to be much less than heavily stocked ponds.

Fourth: Be prepared for this to happen again


If you weren’t ready at all during your first outage, don’t worry. Now is the time to think about gathering supplies for the next one. If you live in an area where long power failures are common, you should consider getting a backup generator for your tanks and house in general. You won’t have access to the internet or any guides on your computer, so it’s best to write this stuff down.

Three most important things are blankets for warmth, battery-powered bubbler for oxygen, and flashlights (headlamps are my favorite). We usually rely on the tank light to observe our fish, but without electricity this is impossible. You will need to keep an eye on them to check for indicators of stress. Always keep extra batteries on hand to operate these electronics. You should always have a good supply of dechlorinator, too.

Another important piece of equipment I keep around is a home-made sponge filter. It serves the purpose of both oxygenating the tank and preserving the good bacteria. I followed this man’s tutorial, and made two filters, one for each of my tanks that uses a power filter. All told it took me about an hour per filter. The supplies were readily available at local chain pet stores and only cost me about $10. A worthy investment in my eyes. In the event of a power outage lasting longer than 3 hours I would set these sponge filters up in my tanks using the media from my filters. The catch about them is, they were difficult to make, and I don’t believe making them during a power outage would be a good idea. So get them made beforehand and put them with your emergency tank supplies. It’s a great idea to keep them all in the same place.

If you are aware of an approaching storm that will probably knock out your power, there are certain things you can do before an outage to help minimize damage. Perform a large water change and stop feeding the fish. Again, these are steps taken to reduce the waste in the aquarium. If you have tropical aquariums, acquiring a few heat packs or thermal blankets isn’t a bad idea, either. Set up everything including the battery-operated pumps, so you won’t be fumbling in the dark when the power does go out. If you have the space, fill old but clean milk jugs and buckets with treated water in case you need to make a water change.

Now I hope you have a better grasp of how to handle a power outage. Just remember: don’t panic and carry a towel. They come in handy for keeping tropical tanks warm and cleaning up those pesky water spills! ;)

Works referenced 


 "Emergencies and your betta: how to prepare." Updated 3 March 2012. Retrieved 26 April 2012.

"TANK EMERGENCY What to do during a power outage." Updated 16 August 2009. Retrieved 26 April 2012.

Wednesday, April 18, 2012

Betta Fish Awareness Day

First off, I would like to apologize for the wait in my publishing of the goldfish care guide and apologize for the long way off the betta fish care guide is. I'm currently dealing with the death of my 14-year-old cat. I don't feel that I can write a long and in-depth article right now. I published the goldfish article on the last night she was with us, but the only reason it was published is because I wrote it before she took a turn for the worse. I'm not going to leave you hanging forever.

In the meantime, you can look over the Betta Fish Awareness Day group on Facebook. Right now it is a small movement to aid in the spread of correct care about betta fish (or Siamese fighting fish). An actual Betta Fish Awareness Day has been set for 21 June in which betta enthusiasts will be out at pet stores trying to spread information about them such as the need for heaters, more than a gallon of water, and weekly water changes.

People (especially new pet owners) go to pet stores thinking they will get reliable advice from employees. Many times this is not the case, but occasionally you will come across a pet store employee who really knows their stuff. What this group wants is for the pet stores to train their employees more about proper betta (and fish in general) care. While I do believe a degree of responsibility lies with the new owner, employees that sell living animals should at least know their basic care. 

Monday, April 16, 2012

Goldfish (Carassius auratus auratus) Care


Goldfish have been domesticated for around 1,000 years. They’ve been domesticated longer than any other fish species. Through the years around 20 breeds of goldfish have developed from the strange, dorsal-less celestial-eyed goldfish to the elegant shubunkin. The most common goldfish you will encounter in the hobby fall into two categories: single-tail (which I often call commons) and double-tail (which I often call fancies). Here are two examples below.

Fancy goldfish; note the shortened body and elongated fins
(pogiebate @

Single-tailed goldfish; note the long
and slender body form (public domain)

For the rest of the article I will be grouping the goldfish into these two tail groups to define the different care requirements for each.

Another category of goldfish that needs mentioning are the sight-impaired goldfish; this includes the bubble-eyes, moors (or dragon-eye), and the celestials. These are generally some of the most sensitive goldfish. It is best to keep them with only other sight-impaired goldfish. Due to their eye shapes these fish are often slow swimmers and will have trouble feeding and competing for food even with some of the other double-tailed goldfish.

Before I talk about the care requirements, I should say something about goldfish size. There are a lot of misconceptions about goldfish, one being that goldfish stay small. This is absolutely false. places the average goldfish length at 12 inches (32 cm). The fish you often see in the store are babies probably no more than a month or two old. Make no mistake. They will be monsters in no time with proper care and food.

Minimum tank requirements

No matter what the sales associate tells you or how your friend was able to keep them, a bowl is not a suitable home for a goldfish! They are often less than a gallon and don’t provide enough surface area for oxygen to diffuse into the water. In fact, a fully grown goldfish couldn’t even fit in a bowl!!

Bowls are not suitable!
Original photo by Luigi Diamanti

At minimum your tank should have 10 gallons (40 L) for each fancy goldfish and an additional 10 gallons (40 L) as a buffer zone. For example, if you want four double-tailed goldfish you are looking at a minimum of a 50 gallon (190 L) tank. Single-tailed goldfish need room as well as gallons. They are fast and like a lot of swimming space. For one single-tailed goldfish you will need a 75 gallon (285 L) tank. A 125 gallon (475) is well-suited for a small group. With their large size and large swimming area needs, they make much better pond fish than aquarium fish.

I know some of you are thinking that if the pet store can cram hundreds of goldfish in a tiny tank, why can’t I? You should not base your fishkeeping habits on pet store displays. The fish are usually only there for a short time which is why the stores can get away with minimal decorations and no plants. It’s the difference between a hotel room and your bedroom. Wouldn’t you feel more comfortable in something personalized to your liking rather than generalized for everyone?

Temperature range

A common misconception about goldfish is that they are coldwater fish. This is untrue. They are temperate fish. The largest difference between a temperate and tropical fish is that the tropicals have a steady, high temperature year round while temperate fish have large fluctuations from close to freezing to around 85F (30C). All this means is that goldfish can live at a wider range of temperature than most fish commonly found in the hobby.

As I mentioned before single-tails and double-tails have different requirements in this department, too. Due to the more sensitive nature of the double-tails they are best kept at temperatures between 70F (21C) and 80F (27C). This may mean that your goldfish need a heater if the tank is in a colder area of the house in the winter time. 

Single-tails are hardy enough to withstand pond life year-round and will survive at temperatures close to freezing and as high as 95F (35C). If they are kept in an aquarium no heater is needed. They can be overwintered inside if the pond is too shallow, but the aquarium must be large enough for them. A 50 gallon (190L) is a good size.

Water quality

This is the most important aspect of having a goldfish. Clean water means a healthy fish. The best way to tell if your water is clean (nope clearness doesn’t count) is to have a home test kit. The drop kits are the best; the strips are just a waste of money. In a goldfish tank the ammonia and nitrite should ALWAYS be 0 ppm. Nitrate can be hard to control because goldfish are so messy, but we aim to keep it under 40 ppm.

The next set of parameters you have to worry about is pH and water hardness (GH and KH). Goldfish may be hardy, but they still have needs. The pH should be above 7. Between 7.2 and 8.2 is ideal. While it is not always necessary to know the exact numbers of your local water hardness, it is important to know that goldfish like hard water which is water with a high mineral content. Their protective coating called a slime coat will slough off in soft water. 

6 month old redcap orandas (Bettasngoldfish @
The only way water quality is maintained is through weekly water changes. There are some older aquarists who will say this is not needed; that line of thought is outdated. All of the current fishkeeping resources recommend weekly water changes. Because goldfish are so messy the weekly water changes should be about 40% to 50% of the tank volume. This means for a 50 gallon (190 L) tank you should take out and replace between 20 gallons (75 L) and 25 gallons (95 L) of water a week.

Filtration is another important aspect of keeping good quality water. A filter than can turn over the volume of the tank 10 times per hour is recommended for goldfish. This can also be accomplished by running two hang on the back (HOB) power filters. I am using this method with my 50 gallon (190L) goldfish tank. Filter brands vary depending on what part of the world you are in, but in the US I have found the AquaClear brand filters to be very reliable.


Water quality has the largest impact on goldfish health, but without a good diet, your fish won’t reach his or her full potential. A high quality food should be used as a staple diet. New Life Spectrum is currently the best pellet food around. And you don’t just need to buy the stuff labeled for goldfish. Any of the diets will do; just make sure they fit inside your goldfish’s mouth and are not floating.

Due to the body shape of fancy goldfish, many experience gastro-intestinal problems associated with pellet food. When this happens, you should switch to gel food. Mazuri gel food is the best commercially available, but many goldfish keepers chose to make their own. It is much more cost-effective and can easily be personalized for the individual fish because like us, some fish don’t like certain foods. It can also be an interesting way to bond with your fish.


This is something most people don’t think about, but watch your goldfish for a little while. They spend a lot of time picking at the substrate and really anything else in the tank. It is important to have a substrate that is either too large to fit in the goldfish’s mouth or small enough to pass through their system if it does get swallowed. I use large river rocks (from a store not the creek as items intended for aquariums have undergone a sterilization process) but have seen other keepers use sand. There are also keepers who have used regular aquarium gravel and never had a problem, but there are confirmed cases of gravel getting caught in the GI tract and killing the goldfish. It is at your discretion as to whether or not you want to take the risk.

Tank mates and compatibility

Goldfish are a very social species and should be kept in groups of 3 or more goldfish, but there are some compatibility issues between the single-tails and double-tails. The single-tails are much faster swimmers and more boisterous and for these reasons, should not be kept with double-tails.

When looking at non-goldfish tankmates for your goldfish you have to consider a few things like adult size, fin-nipping tendencies, and water parameters. Many livebearers such as guppies (Poecilia reticulata) share a lot of the same water parameters (cooler, hard, alkaline water), but they are small enough to be a goldfish snack. And they will be. Goldfish will try to eat anything that fits in their mouth. Personally, I believe that double-tailed goldfish should be kept with just double-tailed goldfish but others have had success keeping them with zebra danio (Danio rerio) and white cloud mountain minnows (Tanichthys albonubes).

Goldfish and koi in pond (Public domain)
For the single-tailed goldfish your options are even more limited. They are a large fish to keep in home aquariums, but would do well with many of the same tankmates as the double-tails. In a pond you can keep koi (Cyprinius carpio) and single-tails together. These fish are closely related and share many of the same requirements. Mosquito fish (Gambusia spp) are another pond fish that can be kept with goldfish. 

There is some debate as to whether or not goldfish can or should be kept in typical tropical tanks. I do not believe this is a good idea for a few reasons, the first being that while goldfish can live at the higher temps in which tropical communities are kept, having them at these temperatures presents a few obstacles. First, at higher temperatures goldfish need to be fed more to maintain the same body weight. More food in means more waste out, and goldfish are messy enough as it is. Many tropicals don’t appreciate the large mess that goldfish make, and some of the more sensitive fish will succumb to it. Second, at a higher temperature goldfish take up more oxygen. Goldfish need a high level of oxygenation in the water, and the warmer the water gets, the less oxygen it holds. The other reason goldfish aren’t good for tropical communities is poor compatibility with most tropicals. Most fish typically chosen for tropical tanks like soft, acidic water, an environment in which goldfish will not thrive. Many are also small enough to become food or will see the long flowing fins as irresistible targets for fin-nipping. There are just too many complications that can come from keeping goldfish in a typical tropical tank, and I highly advise against it.


Most people have heard that goldfish will eat all live plants and will always uproot anything you put in the aquarium. While this does happen some of the time, if you are feeling adventurous you can try plants with your goldfish. Just make sure you have the right lights and lighting schedule. There is more to a planted tank than just throwing plants in there. I will give you some suggestions for plants with the understanding that more research should be done on planted tanks in general.

Of the plants that other goldfish keepers including myself have had success with, the best have been the thick-leaved plants like anubias and amazon swords. I have also had success with fast growing plants like anarcharis and hornwort. It’s usually hit or miss with goldfish and plants. But don’t ever let anyone tell you it can’t be done. Plants are great for keeping good water quality (but won’t eliminate the need for a water change).

Smashing the myths

One of the excuses I hear for someone keeping a goldfish in a one gallon (4 L) bowl or 10 gallon (40 L) tank is that “the fish will grow to the size of the tank.” This is false. It came about because goldfish kept in these small tanks often live in terribly dirty water. As a result of the poor water quality, they typically die anywhere from a few days to a year after they are purchased. The owner usually assumes that “it was the fish’s time anyway.” Due to these poor conditions the fish either grew just a bit or didn’t grow at all. The lack of growth in the small tank leads people to believe that “fish grew to the size of their tank” and then died when it got old. As we know from earlier, this isn’t true as goldfish live between 10 and 20 years and commonly grow 10 inches (25 cm) or larger.

If the fish does survive this ordeal and is either placed in a larger tank by their owner or re-homed to a larger tank, the goldfish will suffer long term effects in the form of stunting. In anecdotal studies using juvenile discus, aquarists have shown that water quality has a greater stunting effect than being kept in a small environment. So if you are reading this and have just put a goldfish in an insufficient tank: there is still hope. Large, daily water changes will ensure good water quality until you can secure your buddy a larger tank. For those on a tight budget, try to look for secondhand tanks.

With a life span comparable to a cat or dog, goldfish are a lengthy investment and may not be for every aquarist. Some people buy them and then learn about their care requirements. If you find yourself with goldfish you no longer want, do try to rehome them before you euthanize them. Many people see goldfish as throw-away fish, but they are not. They are a rather intelligent fish that will recognize the faces that feed them and be shy around new people. They feel pain, bond with their school mates, and show signs of grief when a tank mate is lost. A lot of people don’t like the ephemeral nature of fish, afraid that a child will be sad when his or her “fishy” dies. With a properly cared-for goldfish, that child won’t have to know loss so soon in life and will grow up with wonderful memories of taking care of “fishy” with mommy and daddy.

Works Referenced

"''Carassius auratus'' (Linnaeus, 1758)". Updated 15 Nov 2011. Retrieved 16 April 2012.

Betty (Dataguru). 02 August 2009. “Goldfish Nutrition Part 2: Food and Nutrition.” Retrieved 10 April 2012.

Gay, Jeremy. 25 March 2010. “What do I need for goldfish?” Retrieved 16 April 2012.

Hill, Nathan. 14 May 2011. “Goldfish with tropicals – wrong or right?” Retrieved 15 April 2012.

Muha, Laura. 2006. “Fish Growth vs. Tank Size” in “The Skeptical Fishkeeper” column. Tropical Fish Hobbyist (December).

**Disclaimer** Since there is little to no scientific research about fishkeeping published, much of the hobby today is opinion, but they are opinions given by keepers and breeders who have been doing this longer than some of us have been alive. Temperature ranges and adult sizes are not opinion. They have been scientifically documented.

I publish this in the memory of my cat, Potpourri. While I wrote this article in the days before, I published it on the last night she was with us. She was sitting on my lap and purring. She always loved to watch the fish and had been my constant companion for 14 years. 

Saturday, April 14, 2012

The Short Straw: Goldfish and Bettas

When you walk into a pet store, what is usually the worst fish tank? The feeder goldfish tank. Often times you will find two or more dead fish on the bottom being picked apart by the others and another 5 or more sickly animals clamping their fins and hovering above death. Usually the betta cups aren’t much better. Because of the ease of access, the dead fish are often promptly removed, but you find fish with varying illness from bacterial to fungal infection in different states of health. Some can be saved. Sadly some cannot.

Of all the fish available today, betta fish and goldfish have the worst lot in the hobby. Many of these fish will be bought and taken to improper homes. Often times this is not knowledgeable neglect on the part of the owner. Many pet store employees simply don’t know how to care for these animals and keep regurgitating age-old myths and pushing produces “designed” for these fish. Just because there is a goldfish or betta on the box doesn't mean it's suitable for one. Some of these owners undoubtedly seek help for their pet when they see the fish looking “sad” in his or her tiny allotment of water. There is a good deal of proper information about these animals out there for those willing to seek it.  

Here is a good assortment of websites with ample information on the care of betta fish and/or goldfish: (this is just a forum)

TFK profile on betta fish (also has an active forum)

Many of these sites also have a forum where you can register and ask any questions that aren’t answered by the articles available there. The users in these forums are very understanding with people who start their fish in poor homes. After all, a great number of them started with those same tanks due to poor information from a pet store. 

Many people start their fishkeeping hobby with a goldfish in a 10 gallon tank or 1 gallon bowl. This fish usually dies shortly after it is bought, and the owner seeks out answers online. Sometimes, the owner will get so frustrated that they give up the hobby right there. This is sad to see happen. Due to a lack of knowledge on the part of the pet store employees, someone has completely written off a wonderful and family-friendly hobby.

White female B. splendens (public domain)
I believe we fishkeepers can change this. Through the spread of proper information we can eliminated the easy pet myth about bettas and goldfish. I know I am fighting an uphill battle, but I plan to keep fighting it because I strongly believe in the welfare of animals. I know that if people saw just how beautiful a betta or goldfish can be when allowed to grow and blossom in ideal conditions, they would cast aside the old axioms and join me in the spread of knowledge.

Friday, April 13, 2012


Hello and welcome. I'm Izzy the Fish Girl as I have been affectionately dubbed by my friends. Here I will be primarily writing about the hobby of keeping fish, fish conservation, and fish in general. I will cover a lot of topics that are of great interest to beginners and also write a bit about advanced fishkeeping. I also plan to do "fish profiles" on the fish I keep as well as some not known to the hobby but of interest in our everyday life.

I've been keeping fish for around 6 years now and consider myself of moderate to advanced ability. I got started during my senior year of high school. My biology teacher wanted us to do an experiment that wasn't the same old ones that high schoolers always perform. I chose to see if a fish could run a maze like a mouse can. Well for some unknown reason I chose koi (Cyprinius carpio). In case you are wondering, no. They couldn't run the maze like I thought they would. Anyway, I overwintered them in a heavily filtered 55 gallon tank, and come springtime of my senior year we built a 4000 gallon koi pond in my backyard. Odd that I should start so large and work my way down.

With the koi in the pond, I added two fancy goldfish (Carassius auratus auratus) to my 55 gallon tank. They are still there. When I went away to college I bought myself a Siamese fighting fish (Betta splendens) to keep me company in my dorm and kept him in a heated and filtered 5 gallon tank. I burned up a ton of gas coming home to look after my goldfish and koi, but it was worth it. In college I studied fisheries science and also received a minor in biology.  Most of my formal education actually dealt very little with my hobby. The only parts that I have been able to carry over have been fish physiology.

In the area of fish tanks I currently have my 55 gallon goldfish tank with two goldfish about 6 years old: a calico veiltail and a red and white ryukin. Currently the tank is sparsely planted. I have two divided 10 gallon betta tanks with two males per tank. My mid-sized tank is a 29 gallon tank that houses my population of kuhli loaches (Pangio spp). And the koi pond with 6 koi and a reproducing population of mosquito fish (Gambusia holbrooki). I will post more in-depth articles about my tanks later and will be sure to update them as my tanks change. For now, I leave you with a photo of my koi pond from last summer.